The chicks aren't all the same age or size, the first six (white leghorn, Rhode Island Red, black sex star, and 3 Americaunas) were supposedly a week old when I got them but they are all feathered out now except a few tufts of baby fluff left, but the sex star is half the size of the others from that group. The other 6 (2 buff orp pullets, 2 straight run light brahmas, and 2 straight run silver laced Wyandottes) are just getting their wing feathers and are still tiny. I expect them to be in the house longer so I'll probably have to reintroduce them anyway, but I regularly give them new toys to keep them entertained (mirrors, pine cones, etc) and the bigger girls all take field trips outside when it's warm. The red used to ride around on my dogs back. I got the second group the day after I got the first 6, but it looks like there's a 3 week age difference, I've had them for 3 weeks or so already.